The US-registered cargo aircraft, owned by the Western Global Airlines Company, had last Sunday been en route to South Africa but made an unscheduled stop-over in Harare where the grim discovery was made.
"The body of the deceased and the cargo have been released to the crew after it was established that there is nothing suspicious," police spokeswoman Charity Charamba told journalists.
A pathologist report showed that the unidentified dead man had succumbed to a lack of oxygen due to the high altitude at which planes fly.
The cargo plane, carrying 67 tonnes of cash in millions of rands for the South African Reserve Bank had departed from Liege, Belgium on February 11 and made a stop in Munich to pick up the shipment of cash.
It made another stop-over in Abidjan, Ivory Coast on the same day and went on to Abuja, Nigeria as well as Entebbe, Uganda on February 13, according to the police.
Charamba said Zimbabwe police had taken fingerprints from the body to be sent to Interpol for analysis.
South Africa's ambassador to Zimbabwe, Vusi Mavimbela, had told AFP earlier that the plane was hired from the Florida-based cargo carrier by the South African central bank to carry banknotes printed in Germany, but did not disclose the amount involved.
